Polyolefin resins are generally cheap, and because of their excellent mechanical strength, heat resistance, chemical durability, mold processability, and recyclability, they are utilized in a wide range of fields, such as various industrial materials, auto parts, consumer electronic appliances, and packaging materials. Since polyolefin resins are flammable, various methods have been conventionally proposed for converting polyolefin resins into flame retardant resins, and in recent years, because of the increasing awareness of environmental problems, various methods have been elaborated to convert polyolefin resins into flame retardant resins so as not to generate harmful gases such as halogen gases at the time of combustion. For example, flame-retardant olefin resin compositions have been proposed, in which a metal hydrate, that is a halogen free flame retardant, is mixed into a polyolefin resin, such as polypropylene or a polyethylene resins, or a thermoplastic elastomer. However, in order to obtain flame retardancy that is equivalent to the conventional halogen containing flame retarding materials, there was a necessity to mix a large amount of the metal hydrate. Incorporation of large amount of metal hydrate makes the thus obtained flame-retardant polyolefin resins becomes inferior in mechanical properties such as flexibility, abrasion resistance, low-temperature characteristics, tensile strength, and elongation at break. Therefore, polyolefin resin compositions provided with both sufficient flame retardancy and the aforementioned mechanical properties are demanded.
Accordingly, in order to solve the aforementioned problems, for example, Patent Document 1 has proposed a flame-retardant olefin resin composition comprising a low-crystallinity and flexible α-olefin homopolymer or copolymer and magnesium hydroxide. This flame-retardant olefin resin composition is provided with high flame retardancy by filling with a high concentration of magnesium hydroxide and it has been admitted that the above resin composition is flexible and has excellent low-temperature characteristics and processability.
Patent Document 2 has proposed an abrasion resistant and flame-retardant resin composition comprising an α-olefin (co-) polymer, an ethylene (co-) polymer, a rubber, an inorganic flame retardant, and a polymer including a carboxylic acid group, and the like.
Patent Document 3 has proposed a flame-retardant resin composition containing a propylene resin, a modified styrene thermoplastic elastomer, and a metal hydrate.    [Patent Document 1] Japanese Unexamined Patent Application, First Publication No. Sho 62-167339    [Patent Document 2] Japanese Unexamined Patent Application, First Publication No. Hei 5-239281    [Patent Document 3] Japanese Unexamined Patent Application, First Publication No. 2002-179857